Sperm that are produced by males homozygous for ms(3)K81 , a male sterile mutant of Drosophila melanogaster, are defective in syngamy but are capable of activating eggs to develop gynogenetically. The activated eggs usually produce haploid embryos, but a small fraction (10( -4)-10(-5)) of them give rise to diploid impaternate adults. To know the cytological mechanisms by which these impaternate...

Sexual eukaryotes undergo an alternation between haploid and diploid nuclear phases. In some organisms, both the haploid and diploid phases undergo somatic development and exist as independent entities. Despite recent attention, the mechanisms by which such biphasic life cycles evolve and persist remain obscure. One explanation that has received little theoretical attention is that haploid-dipl...

Molar pregnancy is a gestational trophoblastic disease that belongs to the category of precancerous lesions. On the other end of the spectrum are gestational trophoblastic neoplasms such as invasive mole, choriocarcinoma, placental site trophoblastic tumor and epithelioid trophoblastic tumor, which are considered malignant tumors. Based on defined histopathological criteria, molar pregnancy is ...

Genetic algorithms have been applied to a diverse eld of problems with promising results. While most of these mainly address stationary problems, there's another group where the problem is dynamic, represented by a changing tness function. These class of problems are characterized mainly by a need for a mechanism to adapt to the change. The best approach depends on the nature of the change in t...

In vitro experimental plants obtained by clonal micropropagation of 9 grape somaclones 5 original forms were the material for cytogenetic research. A biological microscope XSP-146TP was used analysis. 823 cases deviation from diploidy observed in total. Significant tissue ploidy meristematic colchicine treatment proembryogenic cells various varieties. The significant direct correlation found be...

We studied the relation between the DNA content of neuroblastoma cells and the response to therapy in 35 infants under one year of age with a diagnosis of neuroblastoma. Using flow cytometric techniques, we found that in 27 cases the primary malignant stem line consisted of neuroblasts with hyperdiploid DNA content, ranging from 1.07 to 2.42 times the finding in normal diploid cells. All remain...

Relatively recent discoveries of the hormone disrupting properties of some pesticides have raised interest in how contemporary pesticide exposures, which primarily take the form of low level environmental or occupational exposures, impact spermatogenesis. The objective of the present review was to summarize results to date of studies examining pesticide effects on human sperm. Outcomes evaluate...

In order to examine how long diploid cells can be maintained in vitro cultivation without any chromosomal aberrations and to evaluate the mechanism of chromosomal heteroploid transformation, changes of chromosomes were studied in the course of serial in vitro transfers in four normal rat liver cell lines. As a result the diploid cells decreased in number gradually at early culture stage and dis...